The purpose of the study was to measure the effectiveness of using a stimulus fading procedure combined with differential reinforcement and extinction to increase fluid consumption in a child with feeding problems (Patel, Piazza, Kelly, Ochsner & Santana, 2001)
The subject of the study was Ray, a six-year-old boy who was diagnosed with pervasive developmental disorder, now reclassified as Autism Spectrum Disorder. Before the beginning of the treatment, Ray was being fed via G-tube although he drank small amounts of water (Patel et al., 2001)
All sessions took place in a private room with a one-way mirror, the patient sat in a high chair and a cup was used to present the beverages; toys were also present during all sessions. Before the initial assessment, Differential Reinforcement for Alternative Behavior (DRA) was used when mouth clean was achieved. Mouth clean was considered reached when no visible liquid was in Rays moth 30 seconds after beverage acceptance. Escape extinction in the form of physical prompting using milk with Carnation Instant Breakfast (CIB) was implemented for 11 sessions and additional 42 sessions alternating between chocolate and vanilla Pediasure. Mouth clean was not achieved as there was no beverage consumption (Patel et al., 2001).
During the water fading assessment, DRA and escape extinction were used. Small drinks of 3.75 ml or approximately ? of a teaspoon of water, CIB, or milk were presented 30 second after initial acceptance, followed by verbal, modeling, and physical prompts. If Ray refused to drink after 30 seconds, pressure was applied to his mandibular joint and the cup was held at Rays lips until consumption occurred. If mouth clean was achieved within 30 seconds, subsequent reinforcement for a length of 20 seconds was given by allowing access to a preferred toy and praise. The process was repeated after reinforcement with sessions lasting five minutes or after the last drink presented within the five-minute session (Patel et al., 2001).
A reversal design was used to evaluate the water-to milk fading procedure. Fading was accomplished by having a consistent consumption of water, gradually increasing the amount of CIB in water, and increasing the amount of milk in the water with the CIB mixture.
In baseline, a cup or eight ounces of milk with CIB and water with CIB were presented just to demonstrate that milk or water with CIB would not be consumed. Following baseline, sessions were conducted with water only to demonstrate that Ray would drink water. Sessions consisting of water-CIB and milk-CIB were conducted after each fading step was completed.
Fading with water and CIB was done by increasing the percentage CIB added to the cup of water. The amount of CIB was increased by 5% first and then by 10% only after three consecutive sessions were 80% or above of mouth clean was obtained in three consecutive sessions. If mouth clean was not achieved at 80% in three consecutive sessions, the CIB percentage was decreased to that of the previous session. The same process was performed with the milk-CIB fading procedure, with increments of 10% of milk to the water-CIB mixture. Fading process was terminated and the water-CIB or milk-CIB sessions were conducted at 100% concentration only if mouth clean was present or above 80% during the reversal session.
Rays mother was introduced to the session, first by being in the room with the therapist, then by the mother directing therapy with the therapist in the room, and finally by the mother conducting the session by herself (Patel et al., 2001).
During baseline, water mouth-clean was 100%, while water-CIB and milk-CIB mouth-clean were at 0%. Mouth clean increased to 80% for all water-CIB reversal session. The process continued with water-CIB and the began fading in the milk. At the time of discharge, Ray was receiving all his required calories orally. Although experimental control was not demonstrated without a doubt and this limits the study, every time a reversal was conducted, the percentage of mouth clean returned to zero for both water-CIB and milk-CIB. Once the fading procedure reached 30% in CIB-water combination, mouth clean increased to 100% but the same rate was not achieved for milk-CIB condition (Patel et al., 2001).
In the future, investigators may wish to focus on assessing if fading without Differential Reinforcement for Alternative Behavior and Extinction would produce similar results. Also the hypothesis that fading, when combined with Differential Reinforcement for Alternative Behavior and Extinction, will result in high occurrences of mouth clean. If the increased in mouth clean to 100% solutions were the result of exposure to the DRA and Extinction components of the sessions, it would be expected that changes in mouth clean percentage for water-CIB and milk-CIB solutions, should have occurred at approximately the same time. The increase mentioned did not happen at the same time (Patel et al., 2001).